Retractable lifting blades for aircraft

ABSTRACT

A rotor blade assembly for providing vertical lift to an aircraft, having a rotor head and a plurality of blades, with each blade attached to a mechanism such as a cam surface, whereby movement of the mechanism causes the radial distance between the distal tip of the attached blade and the center of the rotor head to alter, decreasing or increasing the length of the lifting surface. The blades are moved from a fully extended position providing maximum lift, to a retracted position in which the blades are removed from the airstream. The pitch of the blades may be controlled by a pitch controller to achieve full helicopter responsiveness. A plurality of bladeletts may be positioned near the outer periphery of the rotor head. When they are moved into the airstream, passing air impacts the bladeletts exerting a pressure, causing rotational movement of the rotor blade assembly.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and claims priority to U.S. patentapplication Ser. No. 11/317,855, filed Dec. 22, 2005, which is acontinuation-in-part of and claims the benefit of U.S. patentapplication Ser. No. 10/657,838, filed Sep. 9, 2003, which claims thebenefit of the prior filing date of U.S. provisional patent applicationNo. 60/409,582 filed on Sep. 9, 2002, all of which are hereinincorporated by reference.

FIELD OF THE DISCLOSURE

The disclosure is generally described as a rotorcraft type rotor-headhaving retractable blades, which may be fitted to either a fixed-wing orrotorcraft aircraft.

BACKGROUND OF THE DISCLOSURE

One of the main limitations of rotorcraft aircraft is the flight speedlimitation caused by the physics and mechanics of flight. Theselimitations have plagued the helicopter since its conception. Retreatingblade stall, dissymmetry of lift, leading, lagging, flapping and coningare just some of the forces that limit the top speed of helicopters. Forexample, most helicopters are limited to air speeds of less than 200miles an hour. The present disclosure, the Gerbino Flight System, allowsfixed wing aircraft to be lifted vertically and then translate intoforward flight to speeds in excess of 300 miles an hour, becauseretreating blade stall and other problems are non-existent in that therotating blades are taken out of the airstream in a new and nonobviousway. Once the aircraft is airborne and moving at sufficient forwardspeed to maintain lift, the rotating blades are gradually retracted withforward propulsion provided by one of any number of systems used byfixed wing aircraft to drive the aircraft forward. An aircraft utilizingthe disclosure would have sufficient lifting surfaces to enable it toremain airborne after the rotor blades are fully retracted.

An autogyro incorporating retracting blades is shown in U.S. Pat. No.6,062,508, however, it does not include the features described andclaimed herein, which enable the present disclosure to achieve truehelicopter flight. U.S. Pat. No. 4,913,376 depicts lifting bladesprotruding from a circular planform wing, but again, it does not includecomponents enabling helicopter flight, nor retractable lifting blades.

SUMMARY OF THE DISCLOSURE

In one embodiment of the disclosure, a rotor blade assembly forproviding vertical lift to an aircraft is disclosed, having a rotorhead, a plurality of cam surfaces, a plurality of blades, with eachblade attached to a cam surface, whereby movement of a cam surfacecauses the radial distance between the distal tip of the attached bladeand the center of the rotor head to alter. In this way, the length ofthe lifting surface of each blade can be decreased or increased. In thepreferred embodiment, the blades are moved from a fully extendedposition providing maximum lift, to a fully retracted stowed or parkedposition, in which the blades are completely removed from the airstream.

In another embodiment of the disclosure, an operating cam is rotatablymounted relative to the rotor head. A plurality of cam surfaces areplaced on the operating cam and a blade is attached to each cam surface.As the cam surface moves, it causes the radial distance between thedistal tip of the attached blade and the center of the rotor head toalter. In another embodiment of the disclosure, the blades have bladespars, with each blade spar attached to the cam surface.

In another embodiment of the disclosure, a rotor blade assembly forproviding vertical lift to an aircraft comprises a rotor head, anoperating cam, a plurality of cam surfaces on the operating cam, aplurality of blades, each blade having a root and a tip, each rootattached to the cam surface, whereby movement of the cam surface causesthe radial distance between the distal tip of the attached blade and thecenter of the rotor head to alter.

In yet another embodiment of the disclosure, at least one pitchcontroller is attached to at least one blade, and each such pitchcontroller is connected to a swash plate. The swash plate causes thepitch controller to move, causing the pitch of the corresponding bladeto be altered.

In yet another embodiment of the disclosure, a plurality of bladelettsare positioned near the outer periphery of the rotor head. Thebladeletts have a retracted position wherein substantially all portionsof the bladeletts are within the outer periphery of the rotor head. Abladelett control mechanism for imparting force to the bladeletts isprovided, wherein the force moves a portion of one or more bladelettsbeyond the periphery of the rotor head, whereby passing air impacts thebladeletts exerting a pressure, which causes rotational movement of therotor blade assembly. The bladelett control mechanism may include anactuator and an actuator cable connecting the actuator to the bladelettswhereby energizing the actuator, the cable is caused to transmit a forceto one or more bladeletts moving said the bladeletts beyond theperiphery of the rotor head and into the path of airflow.

In a further embodiment of the disclosure, the rotor blade assemblyincludes a blade spar on each blade, each blade spar is connected to onecam surface, a spar guide having an opening is attached to each bladespar to guide the blade spar in a sliding fit permitting the blade toextend and retract. The blade spar passes through an opening in a pitchcontroller, the opening in the pitch controller having an internal shapesubstantially matching the external shape of the blade spar. A pitchcontrol rod interacts between the pitch controller and the swash plate,whereby the pitch controller controls the pitch of the blade spar withwhich it cooperates. The opening in the pitch controller may berectangular or other shape such as polygonal or oval. The opening mayalso be splined having as few as one spline, or many splines. Thecooperating blade spar would have a matching external shape.

In yet another embodiment of the present disclosure, a rotor bladeassembly for providing vertical lift to an aircraft includes a rotatablewheel to which blades are attached such that movement of the rotatablewheel causes the radial distance between the distal tip of the attachedblade and the center of the rotor head to alter. The rotatable wheelrotates relative to the rotor head. At least one pitch controller isattached to at least one blade. The pitch controller is connected to aswash plate, whereby the swash plate movement alters the pitch of thecorresponding pitch controller.

In a further embodiment of the present disclosure, the spar guide isconnected to the rotor head with a swiveling connector permitting thespar guide to swivel relative to the rotor head as the blade isretracted or extended.

In another embodiment of the present disclosure, the operating cam hasupper and lower plates with cam surfaces on the upper platesubstantially matching corresponding cam surfaces on the lower plate.Each blade spar is positioned between the upper and lower plates. Eachblade spar is attached to a cam surface on the upper plate, and thesubstantially matching cam surface on the lower plate.

In another embodiment of the present disclosure, the operating cam hasupper and lower plates with attachment points on the upper platesubstantially matching corresponding attachment points on the lowerplate. Each blade spar is positioned between the upper and lower plates.Each blade spar is attached to an attachment point on the upper plate,and the substantially matching attachment point on the lower plate.

In a further embodiment of the present disclosure, a rotor bladeassembly for providing vertical lift to an aircraft includes a rotorhead, one or more blades attached to the rotor head, a piston chamber atthe proximal end (nearest to the center of the rotor head) of said oneor more blades, a spar guide on each blade, and a piston on each sparguide cooperating with the piston chamber within the proximal end of theassociated blade, whereby fluid is forced into one side of the pistonchamber driving the associated blade hydraulically in one direction, andwhereby when fluid is forced into the other side of the piston chamberthe blade is driven in the other direction. At least one pitchcontroller is attached to at least one blade, and to the pitchcontroller is connected to a swash plate, wherein movement of the swashplate moves the pitch controller causing the pitch of the correspondingblade to be altered. Alternatively, the hydraulic system may be replacedwith a screw system or an electromechanical actuator.

In yet another embodiment of the present disclosure, the distancebetween the distal end of the blade and the center of the rotor head isshortened by means of a cable attached to the blade. The cable length iscontrolled by a reel or drum.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 Top view of a schematic depicting the major components of therotor head assembly having cam grooves and extended blades.

FIG. 2 The view of FIG. 1 with blades retracted.

FIG. 3A The view of FIG. 1 with bladelett control mechanism included.

FIG. 3B Cross-sectional view of one possible blade shape.

FIG. 4 The view of FIG. 3A with bladeletts deployed.

FIG. 5 Side view of a schematic of a rotor head assembly, partially cutaway.

FIG. 6 Perspective view of a spar guide.

FIG. 6A Side view of an alternative embodiment of the spar guide of FIG.6.

FIG. 7 Perspective view of a pitch horn.

FIG. 7A Side view of an alternative embodiment of the pitch horn of FIG.7.

FIG. 8 Top view of a schematic of an operating cam actuator.

FIG. 9 Side view of a schematic of a drive shaft in a mast.

FIG. 10 Side view of a schematic of an aircraft depicting aninstallation of one embodiment of the present disclosure.

FIG. 11 Side view of a schematic of an aircraft depicting an alternativeinstallation of one embodiment of the present disclosure.

FIG. 11A Front view of the schematic of the aircraft of FIG. 11.

FIG. 12 Top view of a schematic depicting the major components of therotor head assembly having an operating wheel with blades retracted.

FIG. 13 Side view of a telescoping spar assembly, partially cut away.

FIG. 14 Side view of an embodiment having upper and lower operatingcams, partially cut away.

FIG. 15 Side view of an embodiment having an operating drum, partiallycut away.

FIG. 16 Top view of a schematic of an alternative embodiment of anoperating cam having fixed attachment points for the blade anchors, anddepicting a blade in a withdrawn position.

FIG. 17A Perspective view of one embodiment of the spar guide in FIG.16, with swivel assembly.

FIG. 17B Perspective view of an alternative embodiment of the spar guidein FIG. 16, with swivel assembly.

FIG. 17C Perspective view of one embodiment of the pitch horn in FIG.16.

FIG. 17D Perspective view of an alternative embodiment of the pitch hornin FIG. 16.

FIG. 17E Side view of the mounting of the blade anchor of FIG. 16.

FIG. 17F Top view of the pitch horn and spar guide assembly of FIG. 16.

FIG. 18 Perspective view of one embodiment of a pitch horn.

FIG. 19 Exploded view of one embodiment of the pitch horn of FIG. 18.

FIG. 20 Exploded view of one embodiment of the pitch horn of FIG. 18.

FIG. 21 Depiction of alternative pitch control mechanisms.

DETAILED DESCRIPTION OF THE DISCLOSURE

A rotor head assembly 2 of the preferred embodiment is depicted inFIG. 1. The figure is not to scale. FIG. 1 depicts the condition of ahelicopter in flight with the blades fully extended. This figure is aview from the top of the helicopter. The basic components are asfollows. At the center of the drawing is depicted the hollow mast 4,which in the preferred embodiment is a standard helicopter mast. Thedrive shaft (not shown) is within the mast. Around the mast 4 are therotor head bearings (not shown in this view) supporting the rotor headassembly 2. In turn, the operating cam 6 is bearing mounted (not shownin this view) on the rotor head 3 and can be rotated relative to themast 4 and the rotor head assembly 2. Cam grooves 8 are shown, in whichare mounted the proximal ends of the blade spars 10. The drawing showsone means of deploying the blades 12, utilizing cam grooves 8 having oneparticular configuration, but the grooves may be longer or shorter, havea deeper or shallower angle of attack, or may be otherwise configured toachieve the function of applying a force to the proximal ends of theblade spars 10 to control the distance that the blades 12 retract. Asused in this patent, the term “cam” is used in its standard definition,for example as found in Webster's Unabridged Dictionary© 1996, 1998MICRA, Inc.: (a) A turning or sliding piece which, by the shape of itsperiphery or face, or a groove in its surface, imparts variable orintermittent motion to, or receives such motion from, a rod, lever, orblock brought into sliding or rolling contact with it. (b) A curvedwedge, movable about an axis, used for forcing or clamping two piecestogether. (c) A projecting part of a wheel or other moving piece soshaped as to give alternate or variable motion to another piece againstwhich it acts. As the operating cam 6 is rotated, the blade spars 10 aredrawn into the rotor head 3. In this figure, two spar guides 14 confineeach blade spar 10, but the number of spar guides 14 can be greater thantwo, or may even be a single spar guide.

As is typical in helicopters generally, in the preferred embodiment ofthe disclosure the blade spars 10 run through the entire length of theblades 12. The spars are the core structures of the blades, and are madeof a strong material such as stainless steel. The spars 10 run thelength of the blade 12 and could have a honeycomb core covered withaluminum, fiberglass, carbon fiber, or any accepted material orcombination of materials. The spars 10 are generally surrounded by alightweight material such as fiberglass to form the lifting surfaces ofthe blades 12, and the leading edges may be reinforced with titanium, oranother very tough material. However, it is contemplated that blade andblade spar structures may change in years to come as new materials aredeveloped and new manufacturing processes are implemented. The precisestructure of the blades or blade spars is not central to the disclosuresclaimed, which relate primarily to the retraction and extension ofblades, rather than how they are constructed.

The cam system as depicted was chosen because it provides symmetricalretraction and extension of the blades 12 and assures control of theentire blade pitch range at any point through the complete cycle of therotor head. In the drawings, simple pins are shown as the attachmentmeans, or blade anchors 16, for the root of each blade 12 to the camgroove 8. However, the blade anchor 16 may take other forms, such as alubricated fixture riding in the cam. The fixture may be a block (notshown) in the cam groove 8, shaped to ride smoothly in the cam groove 8.It may be made of any material compatible with the materials and theoperating characteristics of the cam 6, which is contemplated in thepreferred embodiment to be stainless steel or titanium. The block,and/or the cam groove 8 may have surfaces lined with a low frictionmaterial to reduce abrasion and wear. The choice of materials willdepend on the operating characteristics of the aircraft, and there aremany possible variations, and would be obvious to persons of ordinaryskill in the art. This block may include a hole or other attachmentmechanism to which a pin or other gripping member may be attached to theblade spar 10.

Another advantage of a cam system is that the blades 12 are allretracted and deployed simultaneously, preventing the inadvertentretraction or deployment in an imbalanced way.

In the preferred embodiment, each spar guide 14 has a central portion 18made of a flexible material, such as an elastomeric (FIG. 6). The sparguides 14 are mounted to the rotor head 2 using any commonly usedmounting mechanism such as a screw, bolt, rivet, etc. fastened throughmounting holes 22. The flexible material within the spar guides allowsrotational movement of the blade spars 10 allowing the pitch of thespars 10, and thereby the blades 12, to be controlled. The pitch iscontrolled by a pitch controller, which, in the preferred embodiment isa pitch horn 24 mounted between the two spar guides 14 and keyed to thespar through pitch horn channel 26. However, alternative constructionsare possible where, for example, there may be more than two spar guides14 and the pitch horn 24 may be located at a position spaced away fromthe spar guides 14. The pitch horn 24 controls the pitch of the bladespars 10 and thereby the blades 12 as is necessary to achievehelicopter-type flight, including vertical ascent and descent, as wellas hovering. Another example of a pitch controller would be an ear (notshown) on the blade 12 or spar 10 connected to a pitch control rod. Thepitch controller may be controlled by a pitch control rod, or (See FIG.21) an electric servo 200, a hydraulic mechanism 200′, pneumatic servo200″ or any combination thereof.

In the preferred embodiment the spar guides 14 are shown with a lining20 made of Teflon or steel, for example, or some other material. Thetolerances between the lining 20 of the spar guide 14 and the bladespars 10 are such that a slidable fit is achieved for guiding the spar10 as it moves between the fully-extended and fully-retracted positions.The spar guide central channel 28 may be any cross-sectional shape thatachieves these objectives. For example, it may be splined to mate withcorresponding splines on the blade spars 10 to allow a slidable fitwhile at the same time firmly securing the blade spars 10 during pitchadjustment. The pitch channel horn 30 in the pitch horn 24 willcorrespond to the shape and configuration of the blade spars 10.

A connection point 32 on each pitch horn 24 is connected to rotor bladepitch controller links such as pitch control rods, which control thepitch of the helicopter blades. In the preferred embodiment, pitchmovement may be between +/−0° to 15°, or as otherwise required for theflight characteristics of the aircraft. During the process of eitherretracting the blades 12 or deploying the blades, the pitch horns 24, incombination with the spar guides 14 and blade spars 10, continue toprovide pitch control for the blades 12 through the pitch links such aspitch control rods 82, which are connected to the swash plate.

Note that the number of spars 10 and blades 12 are not critical to thedisclosure. Any number may be used to achieve the desired lift andflight characteristics, within the parameters of the structure of therotor head 2 and operating cam 6. For example, as few as two blades maybe used, up to many more, such as four, five or a higher number, eventwenty or more in a large diameter assembly used for lifting heavyvehicles.

The bladeletts 34, an accessory and not a necessity to all applicationsof the flight system disclosed but which may be added to allembodiments, in standard flight are normally retracted as shown in FIGS.1, 2 and 3A. The bladeletts 34 provide a safety mechanism as follows. Innormal flight, as the rotor head assembly 2 rotates, it causes theblades 12 to rotate, which thereby provides lift and control for theaircraft. In normal flight, the bladeletts 34 are retracted to provide aclean airflow surface. In the present disclosure, during normal forwardflight, after the aircraft has achieved sufficient forward speed toallow it to remain airborne, without needing the lift created by theblades 12, the blades 12 are withdrawn, and there is no need to continuerotation of the rotor head assembly 2. If desired, the rotor headassembly 2 may be stopped to conserve energy and fuel. However, rotationof the rotor head assembly 2 must be restarted as the aircraft slows, orwhen a decision is made to operate in a typical helicopter mode. Thiscan be achieved returning power to the rotation system. However, in theevent of an engine failure in forward flight, the aircraft can convertto the helicopter mode as follows. The bladeletts 34 will be deployedinto the slipstream and the operating cam 6 deactivated and allowed torotate freely. The bladeletts 34 are shaped to catch air such that theassembly rotates in the proper direction. The blades 12 will then deployby centrifugal force allowing the aircraft to make a safe autorotationlanding. The number of bladeletts 34, their shapes and the angles ofdeployment may be modified from what is shown in the drawings.

A bladelett deployment mechanism is depicted in FIG. 3A. Tension on theactuation cable 36 rotates the bladeletts 34 around their centralmounting holes 38. As rotation speed increases and nominal operating rpmis reached, the blades 12 are deployed electrically, mechanically,hydraulically, pneumatically, or by employing the centrifugal forcegenerated by the rotation to pull the blades 12 from the retractedposition shown in FIG. 3A to a fully deployed position as shown inFIG. 1. Thereafter, the bladeletts 34 can be retracted to provide arelatively clean airflow surface. The number of bladeletts 34 is notcritical to the preferred embodiment. In the preferred embodiment, eachof the bladeletts 34 has a center mounting hole 38 allowing theattachment of the bladelett 34 to the rotor head 3 with sufficientclearances to allow rotational movement of the bladelett 34 relative tothe attaching mechanism. The attaching mechanism may be a bolt, pin,screw, rivet or any other mechanism through the center mounting hole 38that will provide a secure connection while allowing rotational movementof the bladeletts 34. The control end 40 of the bladelett includes anattachment point 42 for a control mechanism or bladelett actuator 44 torotate the bladelett in and out of the air stream.

The bladelett actuator 44 is a servo, which operates electrically,mechanically, hydraulically, magnetically or otherwise. It is attachedto the rotor head 3 and comprises an arm 46, a body 48 that houses theservomechanism and a power source 50, which could be electrical orhydraulic power. When activated, the arm 46 is retracted into theactuator 44, increasing tension on the actuation cable 36, which causesthe bladeletts 34 to rotate around their center mounting holes 38. FIG.3A depicts two actuators 44, which provide redundancy. The bladeletts 34are biased into their retracted positions using any suitable biasingmechanism, such as springs.

The operating cam 6 may be rotated in several different ways. A screwjack system may be employed, a hydraulic actuator could be anotherchoice, a servo motor, a rack and pinion assembly, a worm gear assembly,crossed helical gears, pneumatic or hydraulic or any other means toimpart force to the operating cam to cause rotation. FIG. 8 depicts oneversion of a rotation mechanism, which includes a hydraulic cylinder 52attached to rotor head 3. It is connected to the operating cam 6 by arotation mechanism arm 54 attached to the operating cam 6 by a pin orrotation mechanism bolt 56. Sufficient clearance is provided to allowthe rotation mechanism bolt 56 to rotate relative to operating cam 6.Hydraulic fluid is introduced into the hydraulic cylinder 52 throughfirst and second feed lines 58 and 60 respectively, pressurizing thecylinder to move the rotation mechanism arm 54 either inward or outwardrelative to hydraulic cylinder 52, thereby rotating the operating cam 6either clockwise or counterclockwise, thereby causing the cam grooves 8to move the blade spars 10 and blades 12 either inwardly or outwardly ofthe operating cam 6. The attachment point for the rotation mechanismbolts 6 to the operating cam 6 may be placed anywhere on the operatingcam 6, whether on the outside edge of the operating cam 6 or somewherebetween the outside diameter and inside diameter of the operating cam 6.In the preferred embodiment, the hydraulic cylinder 52 is attached tothe rotor head 3.

As depicted in FIG. 3B in the preferred embodiment, the helicopterblades 12 are cambered in the manner of a wing as opposed to having thestandard elliptical shape of a helicopter blade. This provides improvedlift to drag (L/D) ratio. However, the cross-sectional shape of eachblade may be any shape necessary to achieve the desired flightcharacteristics, and may even change cross-section at various distancesalong the blade from the root to the tip. Depending on the lift andflight characteristics desired, the number of blades could be any numbernecessary, and blade length and cross-sectional shape may be modified asis known in the art.

In the preferred embodiment, the spar guides 14 are depicted as simplestationary devices that have an internal flexibility, which allows forrotational movement of the blade spars 10. However, the spar guide 14may be as depicted in FIGS. 6A, 17A and 17B, or other configurationsthat would be obvious to someone ordinarily skilled in the art, and thepitch horn 24 may be as depicted in FIGS. 7A, 17C, 17D, 18, 19 and 20 orother configurations that would be obvious to someone ordinarily skilledin the art. Specifically, in FIG. 6A, alternative spar guide 14′ has acircular alternative spar guide central channel 28′ in which acompatibly shaped spar guide can move. Similarly to spar guide 14,alternative spar guide 14′ is mounted to the rotor head 2 by fastenersthrough alternative spar guide mounting holes 22′. FIG. 7A depicts acompatible alternative pitch horn 24′, which includes an alternativepitch horn channel 30′ having a key or spline 31 for cooperating with akeyway on the spar. As the alternative pitch horn 24′ is rotated by acontrol rod attached at alternative pitch horn connection point 32′, thekey 31 rotates the spar by exerting force on the surfaces of the keyway.

FIGS. 18, 19 and 20 depict an alternate embodiment of a pitch horn. Asdepicted in FIG. 18, the assembly comprises a swash plate arm 159attached to a pitch link 158 which is in turn attached to a sphericalbearing 155. As the pitch link 158 moves, it causes the pitch horn 24″to move. The pitch horn 24″ movement causes the blade spar 10 and blade12 to rotate about their longitudinal axes as the pitch is changed bythe pitch horn 24″. As can be seen in FIG. 19, the pitch horn 24″ andits bushings 148′ or spar guides have an opening to receive the bladespare 10. Further, referring to FIG. 19, the pitch horn channel 30 inthe pitch horn 24 will correspond to the shape and configuration of theblade spars 10.

Further, the pitch horn 24″ and the bushings 148′ are retained in thepitch arm base 157. As shown in FIG. 19, the pitch arm base 157 issecured to the base plate 160 by the pitch arm base bushing 166 and thesnap rings 162, 162(a). In one embodiment, this allows the pitch armbase 157 to swivel. As can be seen, the aperture in the pitch arm base157 is sized so to provide clearance for the pitch link arm 158. In oneembodiment, the pitch link arm 158 has spherical bearings at the top andbottom and has an adjustable length.

Further, as depicted in FIG. 20, the pitch arm base 157 is attached to alobed operating cam 130 via a spherical bearing 165 and screw 164, whichallows the blade spar 10 to rotate around its longitudinal axis. Thelobed operating cam 130 rotates and causes the blade spars 10 to slidein the pitch controller 24″ and the blades 12 in turn are extendedoutside the outer diameter of the rotor head, or are withdrawn into therotor head (not depicted). The combined pitch controller 24″ and bladespar 10 are mounted on the rotor head 3 in a manner allowing rotation ofeach combined pitch and spar guide controller 62 as the lobed operatingcam 130 is rotated, and also allowing each combined pitch and spar guidecontroller 62 to pitch in reaction to an attached pitch control rod (notshown). The system can be designed to rotate either clockwise orcounterclockwise.

An elevation view of a rotor head assembly 2 of the preferred embodimentis depicted in FIG. 5. The figure is not to scale. The structure of thepresent disclosure surrounds the mast 4. The rotor head assembly 2 movesrelative to the mast on a cam-bearing assembly, which in the preferredembodiment is a ball-bearing type. However, any other type of bearingstructure may be employed provided that it meets the load requirementsof the particular design. In the space along the mast 4 above the uppercam bearing 68 and the retaining nut 72 may be located the upper rotorcover (not shown). The rotor covers provide an aerodynamic envelope forthe rotor blades and the enclosed mechanisms. The rotor covers may alsoprovide lifting body characteristics to the aircraft, but are notessential to the disclosure itself.

The cam-bearing assembly has two major components, the upper cam-bearingassembly 68 and the lower cam-bearing assembly 70. In this drawing, thelower rotor cover 74 is shown at its attachment points affixed byfasteners such as screws 76 shown in FIG. 5.

The swash plate assembly may be any standard construction known in theart. Commonly the swash plate assembly consists of two plates: the fixedswash plate 78 and the rotating swash plates 80. The rotating swashplate 80 rotates with the drive shaft and the rotor's blades. In thepreferred embodiment, the drive shaft, which is inside the mast 4,rotates the rotor head 3, and consequently the blades 12 and the pitchcontrol rods 82, which, by virtue of the fact that they are connected tothe rotating swash plate 80, impart rotation to the rotating swash plate80. The pitch control rods 82 allow the rotating swash plate 80 tochange the pitch of the rotor blades 12. The angle of the fixed swashplate 78 is changed by the cyclic control rod 84 and collective controlrods 86 attached to the fixed swash plate 78. Not all control rods aredepicting in the figures for the sake of clarity. The rods may also betubes, or equivalent structure. The fixed plate's control rods areaffected by the pilot's input to the cyclic and collective controls,which in turn raise or lower the cyclic control rods 84 and collectivecontrol rods 86. The fixed 78 and rotating 80 swash plates are connectedwith a set of bearings (not shown) between the two plates. Thesebearings allow the rotating swash plate 80 to spin on top of the fixedswash plate 78. The mast 4 does not necessarily need to extend all theway to the top of the rotor head assembly 2. The rotor head 3 could besupported by the drive shaft itself. Also, the operating cam 6 itselfcould rest on the drive shaft, and eliminate the need for bearingsbetween the operating cam 6 and the stationary mast 4. However, in thepreferred embodiment, the nonrotating mast 4 provides a strong structureto support the operating cam system.

FIG. 9 depicts one embodiment of a drive shaft 88 inserted through mast4 and fixed to a rotor head drive flange 90 on a rotor head extension92, which is either integral with, or fixedly attached to, the rotorhead 3. The drive shaft 88 has a drive shaft mounting surface 94 whichis attached to the rotor head drive flange 90 by means of fasteners suchas bolts, screws, rivets or equivalent fasteners placed in attachmentholes 96. Thereby, as the drive shaft 88 rotates, the rotor head 3, andthe entire rotor head assembly 2 rotates. The operating cam 6 is allowedto rotate relative to the rotor head extension 92 at a rotatable surface98, such as a bearing.

In another alternative embodiment, the mast 4 may rotate and serve asthe drive shaft. This is a typical construction seen in many helicoptersin existence today. Obviously, in such an embodiment, there would be noneed for bearings between the operation cam and the mast, and the rotorhead and the mast. Either type of design could accommodate thedisclosure described and claimed herein.

FIGS. 10, 11 and 11A depict an installation of the rotor head of thepresent disclosure to a hybrid aircraft configuration. The rotor headassembly 2 is shown in its covered condition with both the upper andlower rotor covers attached. It should be noted that the cover may beconstructed of several components, or several pieces to achieve thedesired aerodynamic effect and to cover the structure within as desired.The aircraft depicted has conventional wings 100 including winglets 102,fan jets 104 and a Fenestron 106. The figures are not to scale, butmerely illustrative. The physical appearance of the aircraft to whichthe device of the present disclosure is attached may be alteredsignificantly from the appearance depicted in the drawings, to meetoperational requirements. A vectored jet may be used instead of theFenestron 106.

FIG. 12 depicts an embodiment, which has an operating wheel 108 insteadof an operating cam 6. Similar to the operating cam embodiment, theoperating wheel 108 rotates relative to the mast 4. The rotation of theoperating wheel 108 moves the blade anchors 16 toward or away from theouter diameter of the rotor head 3. During this rotation, the bladespars 10 slide in the combined pitch and spar guide controllers 62, andthe blades 12 in turn are extended outside the outer diameter of therotor head, or are withdrawn into the rotor head 3. The system can bedesigned to rotate either clockwise or counterclockwise. The operatingwheel actuator may be a hydraulic cylinder 52 with ahydraulically-operated piston, an electromagnet, a system of gearsincluding worm gears, helical gears, spur gears a rack and pinionsystem, or other means for rotating the operating wheel 108, dependingon design choices. The combined pitch and spar guide controllers 62 aremounted on the rotor head 3 in a manner allowing rotation of eachcombined pitch and spar guide controller 62 as the operating wheel 108is rotated, and also allowing each combined pitch and spar guidecontroller 62 to pitch in reaction to an attached pitch control rod (notshown). The drawing is a schematic, not to scale, and shows six blades,but there may be any number of blades, depending on design choices. Theswash plate assembly operates essentially the same as discussedpreviously. The blades can be swept forward or aft (clockwise orcounterclockwise) to the rotation of the system, to be determined byflight tests for each application and type of aircraft.

FIG. 13 depicts an embodiment wherein the spar 10 is retracted and/orextended hydraulically or pneumatically. The proximal end of the spar 10includes a sealed fluid chamber 110 in which a stationary piston 112 isplaced. Fluid is injected into, and drained from, a chamber fore 114 anda chamber aft 116 of the stationary piston 112 through ports connectedto piston hydraulic lines 118, whereby the pressure changes fore and aftof the piston 112 cause the spar to retract or extend. The drawing is aschematic, not to scale, and shows only one blade, but there may be aplurality of blades. The swash plate assembly, including the controlrods, operates essentially the same as discussed previously. Spar guides14 and a pitch control horn 24 operate in essentially the same way asdiscussed previously. The spars may also be telescoping, having forexample, two or three stages. In this configuration, there is no needfor an operating cam or operating wheel. In an alternate construction,instead of hydraulic or pneumatic force, a screw assembly could be used,or a magnetic or electric actuator.

Instead of having one operating cam 6, a plurality may be used. Oneexample is shown in FIG. 14. Upper operating cam 120 and lower operatingcam 122 are depicted. Having upper and lower operating cams balances theforces on the pin riding in the cam groove, and connecting to the spar.The pitch horn 24 and spar guides 14 operate essentially as previouslydiscussed. The slope or rake of the cam groove 8 could be shallow orsteep, (for example as depicted at 8′) depending on operationalparameters and design choices. The drawing is a schematic, not to scale,and shows only one blade, but there may be a plurality of blades. Theswash plate assembly, including the control rods, operates essentiallythe same as discussed previously.

FIG. 15 drawing depicts yet another embodiment, utilizing a drum or reel124 to shorten the length of a cable 126 or flexible connecting element,whereby the spar 10 is drawn closer to the drum, shortening theeffective length of the spar. The figure depicts a worm gear 128,operating the drum or reel 124, but other gear sets could be used, suchas spur gears or crossed helical gears. Any type of servomechanism couldbe used, depending on design choices. The flexible cable could be achain, steel cable, Kevlar belt or some composite material. Centrifugalforce would pull the blade out as the drum or reel 124 is rotated in adirection to increase the length of the cable. The drawing is aschematic, not to scale, and shows only one blade, but there may be aplurality of blades. The swash plate assembly, including the controlrods, operates essentially the same as discussed previously. Spar guides14 and a pitch control horn 24 operate in essentially the same way asdiscussed previously.

FIGS. 16 and 17 depict an embodiment of the disclosure that does notutilize cam grooves on the operating cam. A lobed operating cam 130 isattached to the rotor head assembly in the same manner as the operatingcam 6. In this embodiment, the operating cam 130 includes a recess 142.Blade spars 10 are attached at their roots at each mounting hole 132utilizing either a Lord type (rubber), steel uniball type or Teflon typemounting bearing 134 secured by a mounting bearing bolt 136 andpositioned in recess 142, as depicted in FIG. 17E. This recess portionmay also be formed by a double-layered lobed operating cam 130, having alower layer or plate 131. This type of construction allows the bladespar 10 and blade 12 to rotate about their longitudinal axes as thepitch is changed by the pitch horn, which in FIGS. 16 and 17 is shown ascontrol horn 138. The bearing 134 also allows the blade spar 10 to pivotaround the bearing as the lobed operating cam 130 is rotated to retractor extend the blade spars 10 and blades 12, similarly to the operationof the mechanism shown in FIG. 12. FIG. 16 also depicts reference linesthat show the change in angles of the blade spars and blades from thefully extended position 144 at 0° to a fully retracted position 146 at18°.

The same type mounting bearing 134 may be used in conjunction with anypitch horn or control horn to permit relative rotational movement withthe pitch control rods attached to the pitch horns or control horns. Forexample, a mounting bearing of the type 134 would be inserted into thecontrol horn recess 140 of control horn 138. The mounting bearing wouldthen be attached to a pitch control rod, allowing for horizontal as wellas vertical movement as the blades 12 are retracted and extended.

FIG. 17A depicts a swiveling spar guide 148 having a squarecross-section opening 150 to receive a similarly shaped blade spare 10.A control horn 138 (FIG. 17C) having a similarly shaped opening 152 isattached to the swiveling spar guide 148 with fixed length screws 154which bottom out in screw mounts 156 in spar guide 148. Clearance canthereby be provided between spar guide 148 and control horn 138.Additionally, control horn 138 has arcuate through holes 158 throughwhich the fixed length screws 154 are inserted and said screws thenmounted in screw mounts 156. The clearances provided by thisconstruction limit feed back to the aircraft controls, caused by bladeflapping. The swiveling spar guide 148 includes a flexible insert, suchas elastomeric insert 151, allowing pitch rotation of the spar 10. Theelastomeric insert 151 is lined with a lining 20, as discussedpreviously. The swiveling spar guide 148 is attached to the rotor head32 by a swivel assembly 160 that allows the spar guide 148 to rotate asthe blade spar 10 is retracted and extended.

FIG. 17B is an alternative embodiment of the swiveling spar guide 148,the only difference being that the central opening is a splined opening162, which would mate with a splined blade spar 10. It also includes anelastomeric insert 151 and a lining 21 that is defines the splines. Asplined control horn 139 having a compatible splined control hornopening 164 is attached to the spar guide 148 (FIG. 17D).

It should be noted that the rotor head assembly 2 could be designed toextend and retract the blades 12 in a variety of ways. One way isstraight out in and out from the center of rotation of the operating cam6, as depicted in FIG. 1. The operating cam 6 may rotate eitherclockwise or counter clockwise. FIGS. 12 and 16 depict embodiments thatsweep the blades 12 from a fully extended position to a retractedposition as depicted in FIGS. 12 and 16. The blades 12 may be designedto sweep either forward or rearward in their flight paths. The finaldecision as to whether the rotation is clockwise or counter-clockwisefor the rotor head assembly 2, and whether the blades sweep forward orrearward, or extend and retract along the radius line of the rotor headassembly 2, is directly connected to the shape, size, and weight of thehost aircraft.

In the preferred embodiment, the rotor head is covered with a rotor headcover having an upper portion and a lower portion, which when assembledcould provide an air-foil shape which reduces drag and could provide alifting body for the aircraft. Examples of such completed assemblies canbe seen in FIGS. 10 and 11. The embodiments show only a few examples ofspar guides and pitch horns, but alternative designs may be employed.Other changes may be made to components of the system and would beexpedient design modifications obvious to those skilled in the art.

The disclosure may also be utilized in a counter rotating system, whichhas two sets of rotating blades, one above the other, rotating inopposite directions. In this system the tail rotor is not required.Examples and embodiments of the disclosure as are set forth herein areillustrative and are not intended to be in any way limiting of thedisclosure. The examples are not to be construed as limitations of thepresent disclosure since many variations thereof are possible withoutdeparting from its spirit and scope.

While the apparatus and method have been described in terms of what arepresently considered to be the most practical and preferred embodiments,it is to be understood that the disclosure need not be limited to thedisclosed embodiments. It is intended to cover various modifications andsimilar arrangements included within the spirit and scope of the claims,the scope of which should be accorded the broadest interpretation so asto encompass all such modifications and similar structures. The presentdisclosure includes any and all embodiments of the following claims.

I claim:
 1. A rotor blade assembly for providing vertical lift to anaircraft comprising: a rotor head; an operating wheel rotatable around acentral point, and rotatable relative the rotor head; a plurality ofblades, each blade attached to the operating wheel, each bladecomprising a blade spar; whereby movement of the operating wheel causesthe radial distance between the distal tip of the attached blade and thecenter of the rotor head to alter; and a pitch controller having anopening, said blade spar passing through the opening.
 2. The rotor bladeassembly of claim 1 wherein the pitch controller opening has an internalshape substantially matching the external shape of the blade spar. 3.The rotor blade assembly of claim 1 further comprising an electric servocontrolling the pitch controller.
 4. The rotor blade assembly of claim 1further comprising a hydraulic mechanism controlling the pitchcontroller.
 5. The rotor blade assembly of claim 1 further comprising apneumatic servo controlling the pitch controller.
 6. A rotor bladeassembly for providing vertical lift to an aircraft comprising: a rotorhead; a plurality of cam surfaces; a plurality of blades, each bladeattached to a cam surface, each blade comprising a blade spar; wherebymovement of a cam surface causes the radial distance between the distaltip of the attached blade and the center of the rotor head to alter; anda pitch controller having an opening, said blade spar passing throughthe opening.
 7. The rotor blade assembly of claim 6 further comprisingan electric servo controlling the pitch controller.
 8. The rotor bladeassembly of claim 6 further comprising a hydraulic mechanism controllingthe pitch controller.
 9. The rotor blade assembly of claim 6 furthercomprising a pneumatic servo controlling the pitch controller.
 10. Arotor blade assembly for providing vertical lift to an aircraftcomprising: a rotor head; one or more blades attached to the rotor head;a piston chamber at the proximal end of said one or more blades, nearestto the center of the rotor head; a spar guide on each blade; a piston oneach spar guide cooperating with the piston chamber, whereby fluid isforced into one side of the piston chamber driving the associated bladehydraulically in one direction, and whereby fluid is forced into theother side of the piston chamber driving the associated blade in theother direction; and a pitch controller having an opening, said bladespar passing through the opening.
 11. The rotor blade assembly of claim10 further comprising an electric servo controlling the pitchcontroller.
 12. The rotor blade assembly of claim 10 further comprisinga hydraulic mechanism controlling the pitch controller.
 13. The rotorblade assembly of claim 10 further comprising a pneumatic servocontrolling the pitch controller.